REGENERATION AND REORGANIZATION IN UROLEPTUS MOBILIS FOLLOWING INJURY BY INDUCED ELECTRIC CURRENTS

¹ From Brooklyn College and the Marine Biological Laboratory, Woods Hole, Mass.

1. Uroleptus mobilis organisms were subjected to injury and mutilation by rapidly induced electric currents to determine whether ciliates, drastically injured, would undergo regeneration and reorganization comparable to that following other types of mutilation.

2. Under the influence of the induction current most of the organisms moved abnormally, and were drawn towards the cathode of the break shocks. Disruption and disintegration of the cell bodies occurred, usually, at the posterior region. This resulted in diverse pieces manifesting various degrees of injury.

3. Injured pieces retained their original polarity and moved in essentially the same manner as the entire animal.

4. Within three to eight hours after injury, each fragment had regenerated its missing structures, and at the end of thirty-four hours most of the regenerated individuals were in the process of division.

5. Regeneration was accompanied by profound protoplasmic reorganization changes comparable to those occurring at the time of division. Cortical organelles were withdrawn, and new sets developed in the reformed individuals. The macronuclei fused into a relatively small division nucleus followed by the rapid constriction of the latter into the eight macronuclei characteristic of normal individuals. The micronuclei divided mitotically.

6. The presence of both macronuclear and micronuclear material was necessary for complete functional regeneration in Uroleptus.